- Postcode district
- SG1
- Survey
- Free for new and replacement doors
- Typical lead time
- Typically 6–8 weeks for slimline systems after check survey sign-off
- Guide price
- From £5,095 inc VAT
- Nearby
- Hitchin, Letchworth Garden City, Welwyn Garden City
- Building rules
- England
What sliding doors for extensions offer homes in Stevenage
Before you settle on a door type, it helps to know what sliding doors for extensions do well and what to check before you order.
If your Stevenage builder is about to pour the screed, confirm the finished floor level for the threshold first, because it is very hard to change afterwards.
For a garden room at the bottom of a Stevenage garden, think about access: large glass panels need a clear route from the road to the site.
- A check survey once the opening is built means the door is made to the real dimensions, accounting for any small variation in the brickwork or blockwork.
- Slimline aluminium systems with interlocks typically around 20–25 mm maximise the glass in a new rear wall, keeping the view as open as possible.
- Agreeing a fitting date with your builder lets the extension be made weathertight on programme, so plastering and flooring can follow without waiting on the doors.
Sunlight, glass and orientation in Stevenage
Sun angles matter for big glazed doors. Around Stevenage, midday sun reaches about 62° in summer and drops to about 15° in winter. That low winter sun is free heat through south-facing glass; high summer sun is easier to shade with a roof overhang, and solar-control glass helps where there is none.
What should you budget for sliding doors for extensions in Stevenage?
Guide prices are the same across Hertfordshire. They cover the door supplied and fitted into a prepared opening, including VAT, with options itemised in your quote.
| Overall width | Typical panels | Guide price (fitted, inc VAT) |
|---|---|---|
| 2.4 m | 2 panels | £5,995–£7,295 |
| 3.6 m | 2 panels | £7,795–£9,495 |
| 4.0 m | 3 panels | £8,395–£10,195 |
See every size on the sliding doors for extensions page or try the guide price tool.
Survey, manufacture and fitting around Stevenage
A surveyor visits your Stevenage home to check the wall, the structure above and the floor levels, and talks through glass and finish. Any building work is planned to the engineer's design, the door is made to the finished opening sizes — typically 6–8 weeks for slimline systems after check survey sign-off — and fitting usually takes 1–2 days, scheduled to the build programme.
Rules for sliding doors for extensions in England
In England, sliding doors in a new extension are covered by the extension's own Building Regulations application rather than a separate door notification. Approved Document L limits the glazed area: windows, roof windows and doors should not normally exceed 25% of the extension's floor area plus the area of any windows or doors lost to the extension, unless the extra glass is compensated for elsewhere. The doors must also meet the energy and safety glazing standards.
Options to consider for your sliding door for an extension
- Three or four panels. More panels for wider extension openings, with one or more sliding.
- Two-panel slimline. One sliding and one fixed panel, suiting openings up to around 3.6 m depending on the system.
- Solar-control glass. Coated glass for south- and west-facing extensions prone to summer overheating.
Questions about sliding doors for extensions in Stevenage
How soon can you survey in Stevenage?
Surveys in the SG1 district are booked at a time that suits you, and we offer survey dates when we reply to your enquiry. After you approve the written quote, manufacture is typically 6–8 weeks for slimline systems after check survey sign-off.
Can you measure from drawings rather than the built opening?
We can quote from drawings, but we manufacture from a check survey of the built opening, because real openings often differ slightly from the plans. Making a large made-to-measure door from drawings alone risks it not fitting. If a programme makes that unavoidable, any arrangement and who carries the risk would be agreed in writing first.
How do I get a level threshold in an extension?
A level or flush threshold in an extension needs the finished floor level inside to be set relative to the door sill and the outside paving before the screed goes down. Outside, a drainage channel is needed across the threshold so rain cannot run in. Our thresholds guide explains the options.
How much do sliding doors for an extension cost?
Slimline sliding doors for an extension have a guide price of £7,795–£9,495 for a 3.6 m opening and £9,595–£11,695 for a 4.8 m opening, fitted, inc VAT at standard 2.1 m height. Taller doors, extra panels, special glass and flush thresholds move the price. Your written quote after the check survey fixes it.